Outline

Questionnaire: In the Netherlands all emergency medical services (EMS) are Pre-Hospital Trauma Life Support certified and supply high qualified basic emergency care. Since 1997 helicopter emergency medical services (HEMS) are available to provide in addition to the EMS on-scene assistance to trauma patients. The aim of the HEMS is an upgrade on demand of standard care at the scene if vital signs are at risk. The HEMS is always staffed by an anesthesiologist or trauma surgeon. The HEMS can be primary dispatched by the dispatcher based on sound criteria like suspicion of high energetic trauma, entrapment and drowning and secondary based on patients' conditions as observed by the EMS on scene. Patients are transported to a hospital predominantly by ambulance, while care is given by the HEMS physician. Currently there are four HEMS that cover the Dutch area and can reach about 75% of the Dutch population within 13 minutes.

Because of the Dutch flat country, short distances and a high density of hospitals the EMS dispatcher still can chose well-considered for “scoop and run” without dispatch of the HEMS. Ideally patients treated by the HEMS experience a better outcome. In the current study we investigate the effect of treatment by HEMS on mortality. Difference is made between patients with and without traumatic brain injury (TBI).

Methods: All trauma patients (n=186) between 2003 and 2008 who are treated by the HEMS on the scene and admitted to the study hospital were matched with patients who are treated without assistance of the HEMS in the same period. We matched for Injury Severity Score, age, gender, TBI and mechanism of trauma. The odds ratio (OR) of early trauma fatality (death within one calendar day after trauma) and in-hospital mortality was calculated by using logistic regression. The OR was used to calculate the number of patients needed to treat (NNT) by the HEMS to let survive one more patient. Analysis were done for the total study population and stratified for TBI.

Results and Conclusions: The adjusted OR of early trauma fatality is 0.8 (not significant) for patients both with and without TBI. To let survive one more patient with TBI the first day after the trauma 22 treatments by the HEMS are needed. For patients without TBI the NNT is even 272. The OR of in-hospital mortality is 1.4 for patients with TBI and 0.9 for patients without TBI, both not significant. For patients without TBI one more patient will survive if the HEMS treat 72 patients. However in the group of patients with TBI treatment by the HEMS seems to led to one more dead for every 12 patients.

In conclusion, the study population have a small better chance to survive if treated by the HEMS, but for patients with TBI the outcome seems worse at the end of the hospital admission. Our results suggest that especially these patients still die, although not longer at the scene, but in the hospital.